I am sure the Germans used their arctic bases for stuff other than weather forecasting, but it would probably have been relaying information that German spies in the US or the Soviet Union to Berlin. I seriously doubt that the germans had chemical bases in the norht/south pole, as chemicals don't do well in the cold, and it would be cheaper to make the U-boats go to German controlled docks in Europe than using a pole base to where the allies could easily bomb the transport that are fueling the U-boat pens' that aren't in the poles.
